Pattern Formation in Active Fluids

Active self organization of structure is ubiquitous in nature. In a seminal work, Turing proposed a general reaction diffusion mechanism for pattern formation [2]. The contractile stress generation and resultant pattern formation in actin-myosin cortical layer lying close to cell membrane, controls from cell motility to tissue development. Considering this cortical layer as an active fluid, we first show steady state pattern formation due to competition between diffusive and active contractile processes, following a recent work done by the Julicher group [1]. Starting from a uniform distribution, with\ud increasing activity the system shows a non-equilibrium phase transition to density modulated state. We further investigate the impact of active to passive transformation of the fluid in a stress dependent manner